From: "Adam J. Richter" <adam@yggdrasil.com>
Date: Mon, 4 Nov 2002 14:02:57 -0800
Message-Id: <200211042202.OAA00458@baldur.yggdrasil.com>
To: viro@math.psu.edu
Subject: Re: Patch(2.5.45): Eliminate unchecked kfree(disk->random)
Cc: axboe@suse.de, linux-kernel@vger.kernel.org, tytso@mit.edu
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1318
Lines: 28

Al Viro wrote:
>On Mon, 4 Nov 2002, Adam J. Richter wrote:

>> 	alloc_disk in linux-2.5.45/drivers/block/genhd.c calls
>> rand_initialize_disk, which can set disk->random to NULL on kmalloc
>> failure.  disk_release does a kfree(disk->random) without checking.

>kfree(NULL) is guaranteed to be OK and is a very common idiom.  Talk
>to Linus about that - it's a religious issue and FWIW I'm on the same
>side ("free(NULL) should be allowed").  IIRC, Linus had claimed quite
>a few times that change of kfree() that would break kfree(NULL) would
>be considered as a bug.

	Oops, sorry for not checking that possibility before posting.

	I'd still like to see this patch integrated as a clean-up (it
does delete a few lines and should shrink vmlinux by a few bytes), but
it can certainly wait until post-crunch.

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